What effect do thoughts of death have on a typical person's desire for sex? The short answer is that it depends. Armed with insight from terror management theory and attachment theory, Gurit Birnbaum and her colleagues have made a start unpicking the detail of when and for whom death is an aphrodisiac.

Research on terror management theory has shown that people respond to mortality reminders by bolstering their own cultural view, derogating opposing views, and shoring up their self-esteem. By this account, the effect of death on libidinous desire will depend on the meaning that sex has for a person.

An initial study with 36 women and 40 men in Israel found that thinking about death led the men, but not the women, to say that they'd be more likely (compared with controls who thought about a dentist visit) to take part in a casual, one-night stand with a person they'd met at a pick-up bar. Perhaps, the researchers reasoned, this is because cultural norms dictate that 'sexual conquests' can be a self-esteem boost for men, but less so for women.

A follow-up was similar to the first except the 163 Californian participants were asked to imagine a potential one-night in a more romantic context, after a candle-lit dinner and engaging conversation. In this case, thoughts of death led both men and women to say that they'd be more likely than controls to go ahead with the one-night stand, thus showing how a subtle change in sexual symbolism can alter the relationship between morbid thoughts and sexual desire.

This idea was supported in a third study with 89 men and women who were primed with thoughts of death before considering their willingness to have either physical, hedonistic sex with a long-term partner or romantic, loving sex. This time, thoughts of death, compared with thoughts of a dental visit, increased participants' desire for loving, romantic sex, but not purely physical sex. In fact, there was a slight trend for participants to be put off this latter kind of sex, perhaps because morbid thoughts make some people want to escape their animal nature, not be reminded of it.

Lastly, Birnbaum's team explored the role of attachment style in all this, leading to some complex results. This time, morbid thoughts increased most people's overall sexual desire, unless they had an anxious attachment style (characterised by clingy behaviour driven by self-doubt). For these anxious types, when morbid thoughts did lead to sexual desire it was for reasons of relationship insecurity - i.e. to have sex with a partner as a way to cement the relationship. By contrast, for participants with an avoidant attachment style (characterised by emotional distance and self-reliance) morbid thoughts led to increased desire for sex that would bolster self-estem. For men with an avoidant attachment style, this meant a desire for casual sex.

Taken together the research paints a complex picture in which the effect of death-related thoughts on people's libido depends on the meaning that sex has for them. In turn this meaning is shaped by cultural norms and a person's attachment style. 'Although the present research is an important step toward shedding light on the dual potential of sex for both joy and distress,' the researchers said, 'more research is needed to elucidate its contextual determinants and the psychological mechanisms regulating its expression.'_________________________________